P30, the major surface antigen of the Toxoplasma gondii tachyzoite stage, has been isolated from the parasite and shown to protect mice from a virulent T. gondii challenge. The cDNA encoding P30 had been cloned and expressed in E. coli, producing recombinant protein that was poorly recognized by antibody to native protein. The specific aim of this proposal is to demonstrate that recombinant P30 can be expressed mammalian cells in Sindis virus-based vectors, and that the expressed protein resembles more closely native protein isolated from parasite material. The long term goal of this proposal is to test the immunogenic potential of Sindis-P30 recombinant protein, first in the mouse challenge model followed by testing in target host animal species. Success in this endeavor will allow commercial development of vaccines to prevent Toxoplasmosis in sheep, swine, cattle, and perhaps cats. In addition positive results will extend the experimental and practical utility of the recently developed Sindis virus vector systems.